Method of and apparatus for drawing glass sheets.



W. L. MONRO. METHOD OF AND APPARATUS FOR DRAWING GLASS swans.APPLICATION FILED MAR. 4. 1911.

Patented Dec. 14, 1915.

INVENTOR fliguzlsszi V I a I $6M mnQm u gm. 5.44M a cm...-

TED STATES PATENT OFFICE.

WILLIAM L. MONRO, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WINDOW GLASSMACHINE COMPANY, OF PITTBQBQIL PENNSYLVANIA. A CORPORATION OF NEW JERSEYSpecification of Letters Patent.

Application filed March 4. 1911. Serial No. 612,306.

To all whom it may concern:

Be it known that I, VILLIAW L. Mormo, of Pittsburgh, Allegheny county,Pennsylvania, have invented a new and useful Method of and Apparatus forDrawing (llass Sheets, of which the following is a full, clear, andexact description, reference being bad to the accompanying drawing. inwhich- Figure 1 is a view partly in front elevation, arid partly invertical section, of glassdrawing apparatussuitable for carryingout myinvention; and Figs. 2, 3 and are plan views of ditl'erent forms ofdrawing pots which may be employed.

My invention is designed to provide a novel and practical method ofdrawing sheets of glass. Various attempts have been made prior to myinvention to draw glass in sheet form; but insofar as I am aware, allsuch attempts have proved unsuccessful, for a number of differentreasons. In these at tempts, it has been customary to flow the glassmore or less continuously from a meltmg tank or furnace into a drawingpot or vessel, and to maintain a continuous draw. The resulting glasshas not been of commercial clnu'acter, due to the. fact that it is ropy,streaked or corrugated. This defeet in the glass I believe to be due tothe fact that when the glass is flowed in this manner from a furnaceinto a drawing vessel, it is practically impossible to maintain the bodyof glass from which the draw is made of uniform temperature andcharacter, and the slight variations which necessarily occur produce theserious defects above noted. A further dillicnlty has been the tendencyof the glass sheets to draw thicker at the edges of the sheets, and alsoto draw to a point.

My present invention is designed to overcome these dillicnlties and toprovide a method of drawing glass sheets which is commerciallypractical.

In accordam-c with my invention I employ a reversible drawing pot 2,which is of the general character shown in the patent to Lincoln'lhornburg No. 759,329 of May 10th, 1904, that is to say, it contains aplurality of pot cavities which can be successively moved into drawingposition while. the previously used cavity is being drained or freedfrom the. residue of glass left from the drawing operation. The pot is,hmvevcr, made of general rectangular form, with a relatively narrowdrawing opening, such as shown In e ther 1* igs. 2, 3 or 4; and its formmay be varied so as to provide for varying volumes Patented Dec. .14,1915.

of glass at different places in the pot. Thus a the pot may be madedeeper, or wider at its ends than its central portion, so as to providegreater bodies of glass at these points, or it may be shaped in variousother ways, the purpose being in all cases to provide a sufficient bodyof glass where needed to fill out the edges of the sheet, while at thesame time preventing the formation of beaded or thickened edges,andtending to produce uniformity in thickness.

In Fig. 4 I have shown a form of pot which is formed with enlargements 3at its ends. The form shown in Fig. Zi's generally oval shaped, and ispreferably provided with a, small vertical groove 4 at each end intowhich the glass may draw to prevent the formation of a thick head at theedges there of. This'same expedient may be applied to the rectangularform of pot shown in Fig. 2.

designates a suitable bait carried by the carriage 6 mounted to travelon guides 7.

and actuated .by an electric motor 8. Thi s motor may be made to actuatethe carriage through the gears 9 and spiral drum 10, the

latter providing means for varying the speed of draw.

I also, in accordance with my invention, instead of attempting to make acontinuous draw, draw sheets of relatively short lengths, provide afresh drawing cavity and batch of glass for each drawal, and ladle theglass for each batch directly from the melting tank or furnace into thedrawing pot. In this ladling operation, care. is taken that the outerportions or skin of glass in the ladle are not emptied into the drawingpot. In this manner I provide for each drawing operation, a relativelysmall body of'glass, which,

by the usual application of heat to the drawing pet, can be kept at theproper degree of temperature throughout the drawing operation. I alsoprefer to increase the speed of the draw as shown, for-instance, in Fig.1, which increase may be effected either by hand regulation, orautomatically, during the. drawing operation, in order to secure stillgreater uniformity in the thickness of the glass. Tly carrying out theoperation in this manner. I overcome the dillicnlties which haveheretofore been experienced, and enable other forms of pet known in theart may be employed which will answer the purpose. The sheets may bedrawn singly, or :1. Phirality of sheets may be simi'lltancously drawn.a

What I claim is:---

1. The herein described method of drawing glass sheets, which consistsin ladling a relatively small quantity ofinoltcn glass into a drawingreceptacle, and then drawing arelatively short sheet directly upwardfrom such receptacle while maintaining, a

different volun'ieof glass at dlil'erent points.

across the width as described.

Effl'he herein. described method of drawing glass sheets; which 'consi.sin ladling a relatively"small quantity of molten glass into a. drawingreceptacle, disposing'thc glass in said 'rc ';eptacle to provide avaryof the sheet, substantially in ere-es section of the volume of themolten glass at ditfeI'cn t p-oints across the width ef the sheet beingdrawn, and then drawing a relatively short sheet directly upward fromsuch rccepta-tclefsubstzlntially as described.

if '3. The herein described method of draw ing glass sheets, whichconsists-in ladling a relatively small quantity offnioltcn glass' into ndrawing"receptacle, disposing "the glass in receptacle to provide agreater volume of glass adjacent to the edge por tions of th"e shcetthan at the intermediate portion, and then drawing, a relatia sheetdirectly upward from such 11 substantially as ilescnhed.

li lhe herein described.method of lrawing glass sheets, which consistsin ladling a relativel small (uantit ol' molten "lassrelatively smallquantity of molten glass into a drawing receptacle, then drawing arelatively short sheet directly upward from such receptacle Whilemaintaining a different volume of glass at 'diil'crent points across thewidth of the sheet, and increasing the speed of the draw during thedrawing operation, substantially as described.

6. The herein described method of drawing glass sheets, which consistsin drawing relatively short lengths successively from (li-flcrent(lrawin receptacles, prior to each drawing operation providing acleandrawing receptacle, and ladling into such receptacle a batch ofmoltelrglass free from skin and just sullicient for that particularoperation, substantially described. I

7. A glass drawing-pot, having a narrow oblong cavity whose end Wallarelaterally recessed; substantially as described. 7 In testimony whereofllhave hereunto set my hand.

' WILLIAM L. MONRO. \Vitnesses; v

Anion A. Tami, Ron'r. J. lVHAL-EN.

